Bortezomib in Treating Patients With Metastatic or Recurrent Colorectal Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed adenocarcinoma of the colon or rectum that is incurable with conventional therapy * Metastatic or recurrent disease * At least 1 unidimensionally measurable lesion * At least 20 mm by conventional techniques or at least 10 mm by spiral CT scan * Disease must be accessible to biopsy * No known brain metastases PATIENT CHARACTERISTICS: Age * 18 and over Performance status * ECOG 0-1 OR * Karnofsky 70-100% Life expectancy * More than 3 months Hematopoietic * Absolute granulocyte count at least 1,500/mm\^3 * WBC at least 3,000/mm\^3 * Platelet count at least 100,000/mm\^3 Hepatic * Bilirubin no greater than 1.25 times upper limit of normal (ULN) * AST or ALT no greater than 3 times ULN (less than 5 times ULN if liver metastases present) Renal * Creatinine no greater than 1.25 times UNL OR * Creatinine clearance at least 50 mL/min Cardiovascular * No symptomatic congestive heart failure * No unstable angina pectoris * No cardiac arrhythmia Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No psychiatric illness or social situation that would preclude study compliance * No other uncontrolled concurrent illness * No ongoing or active infection * No other active malignancy within the past 3 years except curatively treated nonmelanoma skin cancer or carcinoma in situ of the cervix * No grade 1 or greater peripheral neuropathy due to prior chemotherapy * No significant traumatic injury within the past 21 days PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * No more than 1 line of prior chemotherapy (including any combination of fluorouracil, irinotecan, and/or oxaliplatin) for metastatic disease * At least 4 weeks since prior chemotherapy (6 weeks for nitrosoureas or mitomycin) and recovered * Prior adjuvant chemotherapy allowed * No concurrent cytotoxic chemotherapy Radiotherapy * More than 4 weeks since prior radiotherapy and recovered * No prior radiotherapy to measurable target lesion unless disease progression has occurred after radiotherapy * No concurrent radiotherapy to the sole site of measurable disease Surgery * More than 21 days since prior major surgery Other * No other concurrent investigational agents * No concurrent combination antiretroviral therapy for HIV-positive patients